The National Institute for Health and Welfare THL said on Monday that the gypsum pond leak at the Talvivaara mining site has no immediate serious effects on human health.

According to THL, people will not be directly exposed to impurities in the lakes and rivers around the mine site or in the lower reaches of the Vuoksi and Oulujoki waterways if they do not use lake or river water for drinking or cooking.

Using the contaminated water for bathing or washing does not cause significant exposure to metals. The metals have no direct effects on the skin in the concentrations found in the surface water.

In a statement released Monday, THL noted that it is unclear whether other, currently unknown impurities in the water are associated with skin symptoms that have been reported in the area previously. It has been and remains the recommendation that lake water in the area around Talvivaara should not be used in saunas since the health effects of the naturally occurring high concentration of manganese in the lake water are not known.

No mercury

The impurities leaking into the surface water from the gypsum pond do not enter directly into the groundwater, and the emissions have presumably no direct impact on the quality of groundwater in the area. The quality of water in wells depends more on the quality of local bedrock than on the quality of surface waters

Eating lake or river fish is the most likely source of exposure to emissions from the gypsum pond. The possible increases in heavy metal concentrations in fish will depend on the extent of the gypsum pond leakage. However, it will be observable only after some time when the emissions have migrated in the waterways. The rate at which fish accumulate heavy metals is, nevertheless, relatively low, with the exception of mercury. Therefore, concentrations of metals in fish increase only slowly. The reported emissions from Talvivaara do not include mercury.

Officials said that it was not thought at this time necessary to issue any general restrictions on consumption of fish, as the real concentrations of impurities in local fish are not yet known. According to THL, there is no need to adopt any additional precautionary measures to safeguard public health due to the gypsum pond leakage. However, heavy metal concentrations in fish in the area should be followed up more extensively than is currently done.

Worry a bigger risk

The gypsum pond leakage has, nevertheless, caused concern, uncertainty, fear and anger because the natural environment is being contaminated, says the National Institute for Health and Welfare, THL.

These have considerable consequences on comfort, welfare and socio-economy and may also affect some people's health through, for example, insomnia and stress.

THL stressed that these harmful effects should not be dismissed or underestimated. A larger group of people is also affected by such harmful effects than by the potential direct health risks of the impurities coming from the gypsum pond leak.